1. Field of the Invention
The present invention relates to a process for fabricating a thin multi-layer circuit board on which can be mounted many electronic parts such as integrated circuits (ICs) and large size integrated circuits (LSIs).
2. Related Art
There has been known a thin multi-layer circuit board which is obtained by forming an insulating layer on a plate-like substrate made of a suitable insulating material and interposing at least two wiring pattern layers in this insulating layer. The two wiring pattern layers are connected to each other at a suitable place through a via and the two wiring pattern layers constitute a predetermined circuit pattern. Moreover, on the surface of the thin multi-layer circuit board are provided electronic part-mounting pads to which can be connected the leads of electronic parts, the electronic part-mounting pads being connected through vias to the wiring pattern layers in the insulating layer.